Described herein is a vehicle seat and particularly a vehicle seat including a seat adjustment device for adjusting the state of a seat.
There are conventionally widely known vehicle seats each of which includes a height device that couples a seat cushion serving as a seating portion of a seat main body to a vehicle body floor side so that the seat cushion is movable up and down.
Generally, the height device includes a pair of front links attached between the seat cushion and the vehicle floor and is provided on a seat front side, and a pair of rear links attached between the seat cushion and the vehicle floor and is provided on a seat back side. The height device is configured to be able to adjust the height of the seat main body with one of the rear links acting as a drive link.
An operation lever operating the driving of the height device is attached to the outside of the drive link in a seat width direction, and a brake unit that restricts the driving of the height device is provided between the drive link and the operation lever (see, for example, Japanese Patent Application Laid-Open No. 2009-12548 (hereinafter, “Document '548”)).
A vehicle seat described in Document '548 mainly includes a seat cushion, a lifter device corresponding to a height device, and a resin garnish covering the seat cushion and the lifter device from the outside in a seat width direction.
An operation lever and a brake unit of the lifter device are arranged at distant positions in a seat front to back direction, and power transmission means for transmitting power from the operation lever to the brake unit is constituted by a parallel four-joint link mechanism.
With the configuration described above, operability for an occupant operating the operation lever improves and the degree of freedom for the arrangement of the operation lever increases, thereby facilitating commoditizing the operation lever and the height device.
However, the vehicle seat including the height device has the following problems. At a time of assembling the height device into the vehicle seat, the position of the assembled height device is possibly deviated by the influence of dimensional tolerances, assembly tolerances, welding tolerances, and the like, of constituent components. Furthermore, the positional deviation of the operation lever possibly adversely influences the appearance of the seat.
Particularly in a case of the vehicle seat described in Document '548, the number of constituent components, such as the parallel four-joint link mechanism, increases despite the improvement in the operability of the operation lever, since the operation lever and the brake unit are arranged at the distant positions. As a result, the positional deviation of the height device tends to occur.
Demand, therefore, rises for a technique capable of facilitating positioning the height device (seat adjustment device) and suppressing the positional deviation thereof when the height device is assembled into the vehicle seat.
Moreover, it is important for the vehicle seat including the height device to provide a good operation feeling as well as the high operability for an occupant's operation of the operation lever. The vehicle seat as described in Document '548, however, is not designed to improve the operation feeling.
Demand, therefore, rises for a technique for improving the operation feeling for the operation lever of the height device (seat adjustment device).